This invention relates generally to dispensers for releasing vaporizable materials into the ambient atmosphere. More particularly, the present invention relates to improvements in heat activated dispensers for releasing vaporizable materials such as fragrances, medications, insecticides or any other desired vaporizable material into the ambient. The present invention also relates generally to a method of manufacture of the inventive heat activated dispenser which provides a dispenser consisting of a unitary self-supporting structure thereby alleviating the necessity of utilizing a substrate, binder or other foreign support structures.
It has been found desirable to provide a dispenser for vaporizable materials which has an extensive useful life while being capable of providing a sustained long-term release of the desired vaporizable material in to the ambient. Additionally, a desirable dispenser should be capable of being utilized with a wide range of vaporizable materials having a broad range of uses. The inventive dispenser should, ideally, be capable of holding a relatively large volume or weight of vaporizable material such as vaporizable liquids having a wide range of viscosities or vaporizable powders, be capable of operating with high temperatures, be thermally insulating for safe handling and controlling the rate of vaporization and be biodegradeable. Further, the inventive dispenser should be capable of receiving heat from an a heat source and be of a configuration adapted to fit over, around or in between, such that it accepts heat from the suitable heat source, such as an ordinary household lightbulb while fitting within the inner configuration of a majority of lamp fixtures commonly found within a home. Finally, the inventive dispenser should be capable of resting on or around the suitable heat source and have a configuration suitable for channeling the generated heat across the inner surface area of the dispenser and into the ambient.
In order to achieve the aforementioned desired properties, it is preferable to utilize a synthetic silicate such as that currently marketed by the Manville Corporation under the trade mark "MICRO-CEL". The useful synthetic silicates are, by nature, very fluffy. This property makes them a very difficult material to handle and prepare. Typically, conventional devices utilize some type of substrate or binder to hold or contain a powdery or fiberous absorbent non-formable material. Conventional absorbant devices and absorbent materials are inadequate because they do not hold sufficient volumes or weights of the vaporizable material, they are non-formable and, therefore, need binders or substrates, or if they are capable of being molded, these devices do not hold sufficient quantities of vaporizable material. The inventive method of manufacturing the inventive dispenser solves the problem of having to use a substrate or binder to support a powdery or fiberous absorbent material. It has been found that the synthetic silicates are capable of being compacted into certain shapes and will become a self-supporting structure when so compacted. Therefore, the method of manufacture of the inventive dispenser is designed to account for the chemical and physical properties of the useful synthetic silicates.